1. Technical Field
The present invention relates to a power module using sintering die attach and a manufacturing method thereof.
2. Description of the Related Art
An existing power module was manufactured by bonding an insulated gate bipolar transistor (IGBT), a diode chip and the like to a copper (Cu) lead frame or a direct bonding Cu (DBC) substrate and electrically connecting between the substrate and the housing by an aluminum (Al) wire bonding method.
At this time, the chip is bonded to the substrate using Sn-based solder.
Therefore, the lower portions of the IGBT and the diode chip are made of metal such as silver (Ag) and gold (Au), which can be easily soldered, and the substrate is finished using metal such as copper (Cu), nickel (Ni) or the like.
However, the existing chip bonding method has difficulties in being applied to a high-power electrical device module due to tin (Sn)-based low thermal conductivity (<60 W/m·k), formation of an inter metallic contact (IMC), and low reliability of a material itself.
In addition, the existing chip bonding method also has a problem of degradation in efficiency due to low radiation characteristics.
Meanwhile, in the power module, most of the heat generated at the time of using thereof is discharged to the substrate through the lower portion of the chip.
In order to radiate heat through the substrate as described above, a bonding material between the chip and the substrate should have excellent radiation characteristics.
If cracks occur in the lower portion of the chip due to long use of the power module, it leads to degradation in radiation characteristics and as a result, it also leads to malfunction of the device, thereby causing economic loss.